I. Technical Field
The present invention relates to a drug injection device.
II. Description of the Related Art
A conventional drug injection device has a main body case, an injection needle let-in/let-out opening that is an opening for letting an injection needle in and out of the main body case, a drug syringe mounting component that is provided inside the main body case and in which a drug syringe is mounted, a piston that is able to move with respect to this drug syringe mounting component, a drive mechanism that drives the piston, and a control circuit that is electrically connected to this drive mechanism. With this drug injection device, when the piston is moved so that sealing rubber within the drug syringe mounting component is pushed, the drug is automatically injected into the patient's body through an injection needle mounted at the distal end side of the drug syringe (see, for example, Kohyo (Japanese Unexamined Patent Publication) No. H11-513586).
However, the injection of the drug is sometimes not carried out properly with a conventional drug injection device. For example, if the user's hand should shake for some reason during drug injection, then the drug cannot be properly injected at the targeted site on the body.
In view of this, it is an object of the present invention to provide a drug injection device with which the injection of a drug can be carried out properly.